This invention relates to a circuit on a curved surface, such as on a helmet, and to a method of forming a portion of the circuit, and more particularly, to a circuit on a curved surface including at least one conductive path integral with the curved surface, and to a method of forming a conductive path on, and integral with, a curved surface.
Presently, circuits are provided only on flat surfaces. This is due to the fact that it has been very difficult to trace and form conductive paths on curved surfaces. Therefore, circuits on curved surfaces typically include a flat circuit board in close proximity to the curved surface. Circuit elements such as light emitting diodes are generally mounted on the curved surface, and the flat circuit board is wired to the circuit elements. Additionally, a battery is typically provided near, and is wired to, the flat circuit board. Wiring from the battery to the flat circuit board, and from the flat circuit board to the circuit elements, enables the flat circuit board to power and operate the circuit elements in a pattern dictated by the circuitry on the flat circuit board.
While these circuits do provide curved surfaces with circuit elements thereon, these circuits are inadequate in many respects. For example, because the circuitry is on a flat circuit board which is not integral with the curved surface, it is necessary to handle the curved surface gently so that the wiring does not disconnect from the circuit elements, the flat circuit board, or the battery. If the curved surface is, in fact, a helmet, such as is shown in U.S. Pat. No. 4,231,079, it is necessary to gently place the helmet over the head and gently remove the helmet from the head in order to prevent the wiring from disconnecting. Furthermore, if the helmet is worn while riding a bicycle, it is possible for the vibrations from the bicycle to cause the wiring to disconnect from the circuit elements, the flat circuit board, or the battery. Of course, if the wiring disconnects, this typically results in a circuit which fails to function properly.
Moreover, these circuits make it necessary to provide or reserve space for the flat circuit board, the battery, and the wiring. For example, if the curved surface is a helmet as shown in U.S. Pat. No. 4,231,079, it is necessary to reserve space within the helmet to accommodate the flat circuit board, the battery, and the wiring therebetween. Therefore, the helmet cannot be designed to precisely fit the head, but instead must be oversized. Not only does oversizing the helmet result in a waste of material, but not designing the helmet to precisely fit the head may result in a helmet which is less effective at protecting the head. Furthermore, the flat circuit board, battery, and wiring within the helmet can injure the wearer of the helmet if the helmet is subjected to impact such as if the helmet is worn while riding a bicycle or motorcycle. Also, the presence of the flat circuit board, battery, and wiring therebetween within the helmet results in the helmet being uncomfortable to the wearer.
The difficulties encountered in the prior art hereinabove are substantially eliminated by the present invention.